In a 1-kilometer race, runner A finishes 50 meters ahead of runner B and beats B by 10 seconds. How long does A take to complete the race?

Explanation

Runner B covers 1000 meters in (1000 × 10) ÷ 50 = 200 seconds. Since A beats B by 10 seconds, A's time is 200 - 10 = 190 seconds.